On the electronic structure of methyl butyrate and methyl valerate

No. 2019-A0010806820 UIDB/00068/2020 PTDC/FIS-AQM/31281/2017Abstract: We present novel results of the analysis of the electronic structure of two aliphatic esters: methyl butyrate and methyl valerate. High-resolution photoabsorption spectra were collected and analyzed over the energy range 4.0–10.8 eV and showed for both the molecules not only a clear band of the HOMO to LUMO transition, but also vibronic structure associated with the first Rydberg-valence transition. Photoelectron spectra recorded from 9 to over 28 eV revealed many ionization states with the first adiabatic ionization energies found to be 9.977 eV and 9.959 eV for methyl butyrate and methyl valerate, respectively. Ab initio calculations have been performed in order to help assign the photoabsorption and photoelectron features. Photolysis life times in the atmosphere were calculated revealing that photolysis is not competitive over hydroxyl radical scavenging in the process of removal of these esters from the atmosphere. Graphical abstract: [Figure not available: see fulltext.]publishersversionpublishe

Uso otimizado de marcadores SSR para identificação varietal de algodoeiro herbáceo

The objective of this work was to identify polymorphic simple sequence repeat (SSR) markers for varietal identification of cotton and evaluation of the genetic distance among the varieties. Initially, 92 SSR markers were genotyped in 20 Brazilian cotton cultivars. Of this total, 38 loci were polymorphic, two of which were amplified by one primer pair; the mean number of alleles per locus was 2.2. The values of polymorphic information content (PIC) and discrimination power (DP) were, on average, 0.374 and 0.433, respectively. The mean genetic distance was 0.397 (minimum of 0.092 and maximum of 0.641). A panel of 96 varieties originating from different regions of the world was assessed by 21 polymorphic loci derived from 17 selected primer pairs. Among these varieties, the mean genetic distance was 0.387 (minimum of 0 and maximum of 0.786). The dendrograms generated by the unweighted pair group method with arithmetic average (UPGMA) did not reflect the regions of Brazil (20 genotypes) or around the world (96 genotypes), where the varieties or lines were selected. Bootstrap resampling shows that genotype identification is viable with 19 loci. The polymorphic markers evaluated are useful to perform varietal identification in a large panel of cotton varieties and may be applied in studies of the species diversity.O objetivo deste trabalho foi identificar marcadores polimórficos de sequências simples repetidas (SSR) para identificação varietal de algodão e avaliação da distância genética entre as variedades. Inicialmente, 92 marcadores SSR foram genotipados em 20 cultivares de algodão do Brasil. Desse total, 38 locos foram polimórficos, dos quais dois deles foram amplificados por um único par de iniciadores; o número médio de alelos por loco foi 2,2. Os conteúdos de informação polimórfica (PIC) e de poder de discriminação (DP) foram, em média, 0,374 e 0,433, respectivamente. A distância genética média foi de 0,397 (mínima de 0,092 e máxima de 0,641). Um painel de 96 variedades originárias de diversas regiões do mundo foi avaliado por 21 locos polimórficos derivados a partir de 17 pares de iniciadores selecionados. Entre essas variedades, a distância genética média foi de 0,387 (mínima de 0 e máxima de 0,786). Os dendrogramas elaborados a partir de média aritmética não ponderada (UPGMA) não refletiram as regiões do Brasil (20 genótipos) ou do mundo (96 genótipos), onde as variedades ou linhagens foram selecionadas. O procedimento de reamostragem bootstrap mostra que a identificação dos genótipos é viável com 19 locos. Os marcadores polimórficos avaliados são úteis na identificação varietal de um painel amplo de variedades de algodão e podem ser aplicados em estudos de diversidade da espécie